Effects of Co-occurring Genomic Alterations on Outcomes in Patients with KRAS-Mutant Non-Small Cell Lung Cancer

Spatial iTME analysis of KRAS mutant NSCLC and immunotherapy outcome

We conducted spatial immune tumor microenvironment (iTME) profiling using formalin-fixed paraffin-embedded (FFPE) samples of 25 KRAS-mutated non-small cell lung cancer (NSCLC) patients treated with immune checkpoint inhibitors (ICIs), including 12 responders and 13 non-responders. An eleven-marker panel (CD3, CD4, CD8, FOXP3, CD68, arginase-1, CD33, HLA-DR, pan-keratin (PanCK), PD-1, and PD-L1) was used to study the tumor and immune cell compositions. Spatial features at single cell level with cellular neighborhoods and fractal analysis were determined. Spatial features and different subgroups of CD68+ cells and FOXP3+ cells being associated with response or resistance to ICIs were also identified. In particular, CD68+ cells, CD33+ and FOXP3+ cells were found to be associated with resistance. Interestingly, there was also significant association between non-nuclear expression of FOXP3 being resistant to ICIs. We identified CD68dim cells in the lung cancer tissues being associated with improved responses, which should be insightful for future studies of tumor immunity.

Current perspectives of KRAS in non-small cell lung cancer

NSCLC has a diverse genomic background with mutations in key proto-oncogenic drivers including Kirsten rat sarcoma (KRAS) and epidermal growth factor receptor (EGFR). Roughly 40% of adenocarcinoma harbor Kras activating mutations regardless of smoking history. Most KRAS mutations are located at G12, which include G12C (roughly 40%), G12V (roughly 20%), and G12D (roughly 15%). KRAS mutated NSCLC have higher tumor mutational burden and some have increased PD-1 expression, which has resulted in better responses to immunotherapy than other oncogenes. While initial treatment for metastatic NSCLC still relies on chemo-immunotherapy, directly targeting KRAS has proven to be efficacious in treating patients with KRAS mutated metastatic NSCLC. To date, two G12C inhibitors have been FDA-approved, namely sotorasib and adagrasib. In this review, we summarize the different drug combinations used to target KRAS G12c, upcoming G12D inhibitors and novel therapies targeting KRAS.

Garsorasib in patients with KRASG12C-mutated non-small-cell lung cancer in China: an open-label, multicentre, single-arm, phase 2 trial

BACKGROUND

Garsorasib (D-1553; InventisBio, Shangai, China), a potent KRASG12C inhibitor, has shown promising antitumour activity in patients with KRASG12C-mutated (ie, Gly12Cys) non-small-cell lung cancer (NSCLC) in a phase 1 study. We report results from a phase 2 study conducted to evaluate the efficacy and safety of garsorasib in patients with locally advanced or metastatic KRASG12C-mutated NSCLC.

METHODS

This open-label, multicentre, single-arm, phase 2 trial enrolled adult patients with KRASG12C-mutated NSCLC who had previously been treated with platinum-based chemotherapy and immune checkpoint inhibitors from 43 hospitals in China. Participants received 600 mg garsorasib orally twice per day. Tumour assessments were performed at baseline, at the end of every two cycles (of 21 days) for the first eight cycles, and at the end of every three cycles thereafter. The primary endpoint was objective response rate (ORR) as assessed by an independent review committee (IRC) following the guidelines in Response Evaluation Criteria in Solid Tumours, version 1.1. Efficacy and safety were assessed in all patients who received at least one dose of garsorasib. This trial is registered at ClinicalTrials.gov, NCT05383898, and is active but no longer recruiting.

FINDINGS

From June 17, 2022, to May 17, 2023, of 225 patients screened for eligibility, 123 patients were enrolled and treated with garsorasib. Of these 123 participants, the median age was 64 years (IQR 59-68), 108 (88%) were male and 15 (12%) were female. At data cutoff (Nov 17, 2023), the median follow-up duration was 7·9 months (IQR 6·3-10·4), and 82 (67%) of 123 patients had discontinued treatment. The IRC-confirmed ORR was 50% (61 of 123 patients; 95% CI 41-59). 117 (95%) of 123 patients reported treatment-related adverse events, with 61 (50%) experiencing grade 3 or higher events. The most common types of adverse events of grade 3 or higher associated with garsorasib were hepatic and gastrointestinal events, including increased liver enzymes, such as aspartate aminotransferase (21 [17%] of 123 participants), alanine aminotransferase (19 [15%] of 123 participants), and gamma-glutamyltransferase (28 [23%] of 123 participants); nausea (2 [2%] of 123 participants); and vomiting (2 [2%] of 123 participants). No new safety signals were identified, and most of the adverse events were well managed.

INTERPRETATION

The results show that garsorasib has a high response rate, long duration of response, and an acceptable and manageable safety profile in patients with previously treated KRASG12C-mutated NSCLC. Garsorasib potentially provides a promising treatment option for this patient population.

FUNDING

InventisBio.

Identification of non-actionable mutations with prognostic and predictive value in patients with advanced or metastatic non-small cell lung cancer

INTRODUCTION

Lung cancer is one of the most prevalent cancers and the leading cause of cancer death. Advanced non-small cell lung cancer (aNSCLC) patients frequently harbor mutations that impact their survival outcomes. There are limited data regarding the prognostic and predictive significance of these mutations on survival outcomes in the real-world setting.

METHODS

This observational retrospective study analyzed de-identified electronic medical records from the Flatiron Health Clinico-Genomic and FoundationCore® databases to identify patients with aNSCLC who initiated first-line immune checkpoint inhibitors (ICI; alone or in combination) or chemotherapy under routine care between 2016 and 2021. The primary objectives were to assess the prevalence of non-actionable mutations and to determine their association with overall survival (OS). Real-world progression-free survival (rwPFS) and real-world response (rwR) were investigated as secondary exploratory outcomes.

RESULTS

Based on an assessment of 185 non-actionable mutations in 2999 patients, the most prevalent mutations were TP53 (70%), KRAS (42%), CDKN2A/B (31%), and STK11 (21%). STK11, KEAP1, and CDKN2A/B mutations were significantly associated with lower rwR, shorter rwPFS and OS. KRAS mutations were clinically associated with shorter rwPFS in CIT-treated patients. Subgroup analysis revealed that fast progressors were significantly more likely to harbor STK11, KEAP1, and CDKN2A/B mutations. Accordingly, long-term survivors (LTS) showed a significantly lower prevalence of these mutations.

CONCLUSION

Our results provide evidence on the prognostic value of STK11, KEAP1, and CDKN2A/B mutations in patients with aNSCLC. Further research is required to better understand the implications of these findings on patient management and future trial design and treatment selection.

Targeted Therapies for Previously "Undruggable" KRAS-Mutated Non-Small Cell Lung Cancer: A Review of Sotorasib and Adagrasib

OBJECTIVE

To evaluate the safety and efficacy of the novel KRAS-targeting agents, sotorasib and adagrasib, in treating KRAS G12C-mutated non-small cell lung cancer (NSCLC).

DATA SOURCES

A comprehensive English-based literature search of PubMed and Clinicaltrials.gov between January 2000 and July 2023 was conducted using the terms sotorasib, Lumakras, AMG 510, adagrasib, Krazati, and MRTX849.

STUDY SELECTION AND DATA EXTRACTION

Relevant prescribing information, clinical trials, and treatment guidelines were evaluated.

DATA SYNTHESIS

Sotorasib and adagrasib received accelerated US Food and Drug Administration (FDA) approval following pivotal phase I/II clinical trials. Sotorasib, a first-in-class KRAS inhibitor, demonstrated an overall response rate (ORR) of 41% and a progression-free survival (PFS) of 6.3 months. In a phase III confirmatory trial, sotorasib showed significantly longer PFS compared with docetaxel (5.6 vs. 4.5 months; P = 0.0017). Adagrasib produced an ORR of 42.9% and a PFS of 6.5 months. Both drugs present unique safety profiles, with common toxicities, including diarrhea, musculoskeletal pain, fatigue, and hepatotoxicity.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

With KRAS mutations being among the most common oncogenic alterations in NSCLC, sotorasib and adagrasib offer new therapeutic avenues for this previously "undruggable" target. Current treatment guidelines list sotorasib and adagrasib as second-line options in patients with confirmed KRAS G12C-mutated NSCLC. Additional studies are required to further differentiate the safety and efficacy profiles of these 2 agents and identify their optimal place in therapy.

CONCLUSION

Sotorasib and adagrasib demonstrated promising outcomes in targeting the constitutively active KRAS G12C oncogenic driver, underscoring the need for further research to optimize their therapeutic application in this high-risk population.

Cytosolic DNA sensor AIM2 promotes KRAS-driven lung cancer independent of inflammasomes

Constitutively active KRAS mutations are among the major drivers of lung cancer, yet the identity of molecular co-operators of oncogenic KRAS in the lung remains ill-defined. The innate immune cytosolic DNA sensor and pattern recognition receptor (PRR) Absent-in-melanoma 2 (AIM2) is best known for its assembly of multiprotein inflammasome complexes and promoting an inflammatory response. Here, we define a role for AIM2, independent of inflammasomes, in KRAS-addicted lung adenocarcinoma (LAC). In genetically defined and experimentally induced (nicotine-derived nitrosamine ketone; NNK) LAC mouse models harboring the KrasG12D driver mutation, AIM2 was highly upregulated compared with other cytosolic DNA sensors and inflammasome-associated PRRs. Genetic ablation of AIM2 in KrasG12D and NNK-induced LAC mouse models significantly reduced tumor growth, coincident with reduced cellular proliferation in the lung. Bone marrow chimeras suggest a requirement for AIM2 in KrasG12D-driven LAC in both hematopoietic (immune) and non-hematopoietic (epithelial) cellular compartments, which is supported by upregulated AIM2 expression in immune and epithelial cells of mutant KRAS lung tissues. Notably, protection against LAC in AIM2-deficient mice is associated with unaltered protein levels of mature Caspase-1 and IL-1β inflammasome effectors. Moreover, genetic ablation of the key inflammasome adapter, ASC, did not suppress KrasG12D-driven LAC. In support of these in vivo findings, AIM2, but not mature Caspase-1, was upregulated in human LAC patient tumor biopsies. Collectively, our findings reveal that endogenous AIM2 plays a tumor-promoting role, independent of inflammasomes, in mutant KRAS-addicted LAC, and suggest innate immune DNA sensing may provide an avenue to explore new therapeutic strategies in lung cancer.

Resistance to KRAS inhibition in advanced non-small cell lung cancer

Lung cancer remains the leading cause of cancer death globally. More than 50% of new cases are diagnosed in an advanced or metastatic stage, thus contributing to the poor survival of such patients. Mutations in the KRAS (Kirsten rat sarcoma virus) gene occur in nearly a third of lung adenocarcinoma and have for decades been deemed an 'undruggable' target. Yet, in recent years, a growing number of small molecules, such as the GTPase inhibitors, has been investigated in clinical trials of lung cancer patients harboring KRAS mutations, yielding promising results with improved outcomes. Currently, there are only two approved targeted therapies (adagrasib and sotorasib) for advanced or metastatic KRAS-mutated NSCLC from the second-line setting onwards. In this narrative review, we will focus on KRAS, its molecular basis, the role of its co-mutations, clinical evidence for its inhibition, putative mutation to resistance, and future strategies to overcome resistance to KRAS inhibition.

Targeting KRASG12D mutation in non-small cell lung cancer: molecular mechanisms and therapeutic potential

Lung malignant tumors are a type of cancer with high incidence and mortality rates worldwide. Non-small cell lung cancer (NSCLC) accounts for over 80% of all lung malignant tumors, and most patients are diagnosed at advanced stages, leading to poor prognosis. Over the past decades, various oncogenic driver alterations associated with lung cancer have been identified, each of which can potentially serve as a therapeutic target. Rat sarcoma (RAS) genes are the most commonly mutated oncogenes in human cancers, with Kirsten rat sarcoma (KRAS) being the most common subtype. The role of KRAS oncogene in NSCLC is still not fully understood, and its impact on prognosis remains controversial. Despite the significant advancements in targeted therapy and immune checkpoint inhibitors (ICI) that have transformed the treatment landscape of advanced NSCLC in recent years, targeting KRAS (both directly and indirectly) remains challenging and is still under intensive research. In recent years, significant progress has been made in the development of targeted drugs targeting the NSCLC KRASG12C mutant subtype. However, research progress on target drugs for the more common KRASG12D subtype has been slow, and currently, no specific drugs have been approved for clinical use, and many questions remain to be answered, such as the mechanisms of resistance in this subtype of NSCLC, how to better utilize combination strategies with multiple treatment modalities, and whether KRASG12D inhibitors offer substantial efficacy in the treatment of advanced NSCLC patients.

LKB1 Loss Correlates with STING Loss and, in Cooperation with β-Catenin Membranous Loss, Indicates Poor Prognosis in Patients with Operable Non-Small Cell Lung Cancer

To investigate the incidence and prognostically significant correlations and cooperations of LKB1 loss of expression in non-small cell lung cancer (NSCLC), surgical specimens from 188 metastatic and 60 non-metastatic operable stage I-IIIA NSCLC patients were analyzed to evaluate their expression of LKB1 and pAMPK proteins in relation to various processes. The investigated factors included antitumor immunity response regulators STING and PD-L1; pro-angiogenic, EMT and cell cycle targets, as well as metastasis-related (VEGFC, PDGFRα, PDGFRβ, p53, p16, Cyclin D1, ZEB1, CD24) targets; and cell adhesion (β-catenin) molecules. The protein expression levels were evaluated via immunohistochemistry; the RNA levels of LKB1 and NEDD9 were evaluated via PCR, while KRAS exon 2 and BRAFV600E mutations were evaluated by Sanger sequencing. Overall, loss of LKB1 protein expression was observed in 21% (51/248) patients and correlated significantly with histotype (p < 0.001), KRAS mutations (p < 0.001), KC status (concomitant KRAS mutation and p16 downregulation) (p < 0.001), STING loss (p < 0.001), and high CD24 expression (p < 0.001). STING loss also correlated significantly with loss of LKB1 expression in the metastatic setting both overall (p = 0.014) and in lung adenocarcinomas (LUACs) (p = 0.005). Additionally, LKB1 loss correlated significantly with a lack of or low β-catenin membranous expression exclusively in LUACs, both independently of the metastatic status (p = 0.019) and in the metastatic setting (p = 0.007). Patients with tumors yielding LKB1 loss and concomitant nonexistent or low β-catenin membrane expression experienced significantly inferior median overall survival of 20.50 vs. 52.99 months; p < 0.001 as well as significantly greater risk of death (HR: 3.32, 95% c.i.: 1.71-6.43; p <0.001). Our findings underscore the impact of the synergy of LKB1 with STING and β-catenin in NSCLC, in prognosis.

Clinicopathologic features, concurrent genomic alterations, and clinical outcomes of patients with KRAS G12D mutations in resected lung adenocarcinoma

BACKGROUND

In light of the ongoing clinical development of KRAS G12D-specific inhibitors, we sought to investigate the clinicopathologic, co-occurring genomic features and outcomes of patients with KRAS G12D-mutant lung adenocarcinoma.

METHODS

3828 patients with completely resected primary lung adenocarcinomas were examined for KRAS mutations between 2008 and 2020. The association between KRAS G12D and clinicopathologic features, molecular profiles, and outcomes was investigated.

RESULTS

65 patients (1.7%) with KRAS G12D-mutant lung adenocarcinoma were identified. KRAS G12D mutation was more frequent in males, former/current smokers, radiologic solid tumors, and invasive mucinous adenocarcinoma. TP53 and STK11 were the two most frequent concomitant mutations in the KRAS G12D group. KRAS G12D mutation did not appear to be a prognostic factor in resected stage I-III lung adenocarcinomas, while KRAS non-G12D mutation was related to worse survival, especially in stage I tumors. KRAS G12D mutations were associated with positive but low (1-49%) PD-L1 expression compared to negative (<1%), while KRAS non-G12D mutation was associated with high PD-L1 expression (≥50%). TP53 co-mutation indicated higher PD-L1 expression, while STK11 co-mutation had a negligible impact on PD-L1 expression. Furthermore, data mining of MSK datasets from cBioPortal revealed that KRAS G12D and SKT11 co-mutation were associated with a diminished response to immunotherapy.

CONCLUSIONS

KRAS G12D-mutant lung adenocarcinoma harbored unique clinicopathologic and genomic characteristics. Despite not being prognostic in resected lung adenocarcinoma, KRAS G12D might be a valuable biomarker in combination with certain co-mutations for identifying relevant subgroups of patients that could eventually influence treatment regimens.

Clinical Utility of Circulating Tumor DNA in Patients With Advanced KRASG12C-Mutated NSCLC Treated With Sotorasib

INTRODUCTION

For patients with KRASG12C-mutated NSCLC who are treated with sotorasib, there is a lack of biomarkers to guide treatment decisions. We therefore investigated the clinical utility of pretreatment and on-treatment circulating tumor DNA (ctDNA) and treatment-emergent alterations on disease progression.

METHODS

Patients with KRASG12C-mutated NSCLC treated with sotorasib were prospectively enrolled in our biomarker study (NCT05221372). Plasma samples were collected before sotorasib treatment, at first-response evaluation and at disease progression. The TruSight Oncology 500 panel was used for ctDNA and variant allele frequency analysis. Tumor response and progression-free survival were assessed per Response Evaluation Criteria in Solid Tumors version 1.1.

RESULTS

Pretreatment KRASG12C ctDNA was detected in 50 of 66 patients (76%). Patients with detectable KRASG12C had inferior progression-free survival (hazard ratio [HR] 2.13 [95% confidence interval [CI]: 1.06-4.30], p = 0.031) and overall survival (HR 2.61 [95% CI: 1.16-5.91], p = 0.017). At first-response evaluation (n = 40), 29 patients (73%) had a molecular response. Molecular nonresponders had inferior overall survival (HR 3.58 [95% CI: 1.65-7.74], p = 0.00059). The disease control rate was significantly higher in those with a molecular response (97% versus 64%, p = 0.015). KRAS amplifications were identified as recurrent treatment-emergent alterations.

CONCLUSIONS

Our data suggest detectable pretreatment KRASG12C ctDNA as a marker for poor prognosis and on-treatment ctDNA clearance as a marker for treatment response. We identified KRAS amplifications as a potential recurring resistance mechanism to sotorasib. Identifying patients with superior prognosis could aid in optimizing time of treatment initiation, and identifying patients at risk of early progression could allow for earlier treatment decisions.

Emerging Therapies in Kirsten Rat Sarcoma Virus (+) Non-Small-Cell Lung Cancer

Kirsten rat sarcoma virus (KRAS) is the most frequently found oncogene in human cancers, including non-small-cell lung cancer (NSCLC). For many years, KRAS was considered "undruggable" due to its structure and difficult targeting. However, the discovery of the switch II region in the KRAS-G12C-mutated protein has changed the therapeutic landscape with the design and development of novel direct KRAS-G12C inhibitors. Sotorasib and adagrasib are FDA-approved targeted agents for pre-treated patients with KRAS-G12C-mutated NSCLC. Despite promising results, the efficacy of these novel inhibitors is limited by mechanisms of resistance. Ongoing studies are evaluating combination strategies for overcoming resistance. In this review, we summarize the biology of the KRAS protein and the characteristics of KRAS mutations. We then present current and emerging therapeutic approaches for targeting KRAS mutation subtypes intending to provide individualized treatment for lung cancer harboring this challenging driver mutation.

Prognostic and predictive biomarkers with therapeutic targets in nonsmall-cell lung cancer: A 2023 update on current development, evidence, and recommendation

BACKGROUND

Since the publication of the original work in 2014, significant progress has been made in the characterization of genomic alterations that drive oncogenic addiction of nonsmall cell lung cancer (NSCLC) and how the immune system can leverage non-oncogenic pathways to modulate therapeutic outcomes. This update evaluates and validates the recent and emerging data for prognostic and predictive biomarkers with therapeutic targets in NSCLC.

DATA SOURCES

We performed a literature search from January 2015 to October 2023 using the keywords non-small cell lung cancer, clinical practice guidelines, gene mutations, genomic assay, immune cancer therapy, circulating tumor DNA, predictive and prognostic biomarkers, and targeted therapies.

STUDY SELECTION AND DATA EXTRACTION

We identified, reviewed, and evaluated relevant clinical trials, meta-analyses, seminal articles, and published clinical practice guidelines in the English language.

DATA SYNTHESIS

Regulatory-approved targeted therapies include those somatic gene alterations of EGFR ("classic" mutations, exon 20 insertion, and rare EGFR mutations), ALK, ROS1, BRAF V600, RET, MET, NTRK, HER2, and KRAS G12C. Data for immunotherapy and circulating tumor DNA in next-generation sequencing are considered emerging, whereas the predictive role for PIK3CA gene mutation is insufficient.

CONCLUSIONS

Advances in sequencing and other genomic technologies have led to identifying novel oncogenic drivers, novel resistance mechanisms, and co-occurring mutations that characterize NSCLC, creating further therapeutic opportunities. The benefits associated with immunotherapy in the perioperative setting hold initial promise, with their long-term results awaiting.

Outcomes in patients treated with frontline immune checkpoint inhibition (ICI) for advanced NSCLC with KRAS mutations and STK11/KEAP1 comutations across PD-L1 levels

INTRODUCTION

In patients with advanced NSCLC (aNSCLC), the impact of KRAS mutations (m) and comutations with STK11 and KEAP1 on outcomes across different PD-L1 levels remains incompletely understood. We aimed to investigate the frequency of KRAS mutations and comutations across PD-L1 levels, and the association between these mutations and survival, stratified by PD-L1 expression.

METHODS

We conducted a nationwide cohort study of patients diagnosed with aNSCLC between 2016 and 2021 treated with frontline (chemo)immunotherapy, who underwent molecular genotyping including KRAS, STK11, and KEAP1. Real-world overall survival (OS) and progression-free survival (rwPFS) were estimated using Kaplan-Meier methodology. Cox multivariable regressions were used to evaluate the association between KRASm and survival across different PD-L1 strata, and to assess whether the association between KRASm and survival differed by PD-L1 level. Finally, within subgroups defined by PD-L1 expression, we used interaction terms to assess whether co-mutations with STK11 and KEAP1 moderated the association between KRAS mutation and survival.

RESULTS

Of our 2593-patient cohort, 982 (37.9 %) were KRASm and 1611 (62.1 %) KRASwt. KRASm were enriched in the PD-L1 ≥50 % cohort (334/743, 45 %), but within patients with KRASm, co-mutations with STK11 and KEAP1 were enriched in the PD-L1 0 % cohort. KRASm was associated with significantly worse OS in the PD-L1 0 % cohort compared to the PD-L1 ≥50 % cohort (P for interaction = 0.008). On adjusted analyses stratified by PD-L1, KRASm was associated with worse survival only in the PD-L1 0 % group (OS HR 1.46, p = 0.001). KEAP1 and STK11 comutations were most strongly associated with worse OS in the PD-L1 0 % subgroup; patients with triple KRASm/KEAPm/STK11m PD-L1 0 % NSCLC experienced the worst outcomes.

CONCLUSIONS

KRASm are associated with worse overall survival in PD-L1 negative NSCLC; however, this association is largely driven by comutations with STK11 and KEAP1, which are enriched in PD-L1 negative tumors.

Impact of KRASG12D subtype and concurrent pathogenic mutations on advanced non-small cell lung cancer outcomes

PURPOSE

Mutations in the Kirsten rat sarcoma viral (KRAS) oncogene constitute a significant driver of lung adenocarcinoma, present in 10-40% of patients, which exhibit heterogeneous clinical outcomes, mainly driven by concurrent genetic alterations. However, characterization of KRAS mutational subtypes and their impact on clinical outcomes in Latin America is limited.

METHODS

A cohort study was conducted at the National Cancer Institute (INCan) of Mexico. Individuals with advance-staged of adenocarcinoma and KRAS mutations, detected by next-generation sequencing, having undergone at least one line of therapy were included for analysis. Clinical and pathological characteristics were retrieved from institutional database from June 2014 to March 2023.

RESULTS

KRAS was identified in fifty-four (15.6%) of 346 patients, among which 50 cases were included for analysis. KRASG12D (n = 16, 32%) and KRASG12C (n = 16, 32%) represented the most prevalent subtypes. KRASG12D mutations were associated with female (p = 0.018), never smokers (p = 0.108), and concurrences with EGFR (25.0% vs. 17.6%, p = 0.124) and CDKN2A (18.8% vs. 14.7%, p = 0.157). KRASG12D patients showed a better ORR (66.6% vs. 30.0%; OR 4.66, 95% CI 1.23-17.60, p = 0.023) and on multivariate analysis was significantly associated with better PFS (HR 0.36, 95% CI 0.16-0.80; p = 0.012) and OS (HR 0.24, 95% CI 0.08-0.70; p = 0.009).

CONCLUSIONS

To our knowledge, this study represents the first effort to comprehensively characterize the molecular heterogeneity of KRAS-mutant NSCLC in Latin American patients. Our data reinforce the current view that KRAS-mutated NSCLC is not a single oncogene-driven disease and emphasizes the prognostic impact of diverse molecular profiles in this genomically defined subset of NSCLC. Further validation is warranted in larger multicenter Latin American cohorts to confirm our findings.

Molecular mechanisms underlying the regulation of tumour suppressor genes in lung cancer

Tumour suppressor genes play a cardinal role in the development of a large array of human cancers, including lung cancer, which is one of the most frequently diagnosed cancers worldwide. Therefore, extensive studies have been committed to deciphering the underlying mechanisms of alterations of tumour suppressor genes in governing tumourigenesis, as well as resistance to cancer therapies. In spite of the encouraging clinical outcomes demonstrated by lung cancer patients on initial treatment, the subsequent unresponsiveness to first-line treatments manifested by virtually all the patients is inherently a contentious issue. In light of the aforementioned concerns, this review compiles the current knowledge on the molecular mechanisms of some of the tumour suppressor genes implicated in lung cancer that are either frequently mutated and/or are located on the chromosomal arms having high LOH rates (1p, 3p, 9p, 10q, 13q, and 17p). Our study identifies specific genomic loci prone to LOH, revealing a recurrent pattern in lung cancer cases. These loci, including 3p14.2 (FHIT), 9p21.3 (p16INK4a), 10q23 (PTEN), 17p13 (TP53), exhibit a higher susceptibility to LOH due to environmental factors such as exposure to DNA-damaging agents (carcinogens in cigarette smoke) and genetic factors such as chromosomal instability, genetic mutations, DNA replication errors, and genetic predisposition. Furthermore, this review summarizes the current treatment landscape and advancements for lung cancers, including the challenges and endeavours to overcome it. This review envisages inspired researchers to embark on a journey of discovery to add to the list of what was known in hopes of prompting the development of effective therapeutic strategies for lung cancer.

KRASG12C Inhibitor as a Treatment Option for Non-Small-Cell Lung Cancer with Comorbid Interstitial Pneumonia

Non-small-cell lung cancer (NSCLC) with comorbid interstitial pneumonia (IP) is a population with limited treatment options and a poor prognosis. Patients with comorbid IP are at high risk of developing fatal drug-induced pneumonitis, and data on the safety and efficacy of molecularly targeted therapies are lacking. KRAS mutations have been frequently detected in patients with NSCLC with comorbid IP. However, the low detection rate of common driver gene mutations, such as epidermal growth factor receptor and anaplastic lymphoma kinase, in patients with comorbid IP frequently results in inadequate screening for driver mutations, and KRAS mutations may be overlooked. Recently, sotorasib and adagrasib were approved as treatment options for advanced NSCLC with KRASG12C mutations. Although patients with comorbid IP were not excluded from clinical trials of these KRASG12C inhibitors, the incidence of drug-induced pneumonitis was low. Therefore, KRASG12C inhibitors may be a safe and effective treatment option for NSCLC with comorbid IP. This review article discusses the promise and prospects of molecular-targeted therapies, especially KRASG12C inhibitors, for NSCLC with comorbid IP, along with our own clinical experience.

Tumor mutational burden for the prediction of PD-(L)1 blockade efficacy in cancer: challenges and opportunities

Tumor mutational burden (TMB) is a biomarker that measures the number of somatic mutations in a tumor's genome. TMB has emerged as a predictor of response to immune checkpoint inhibitors (ICIs) in various cancer types, and several studies have shown that patients with high TMB have better outcomes when treated with programmed death-ligand 1-based therapies. Recently, the Food and Drug Administration has approved TMB as a companion diagnostic for the use of pembrolizumab in solid tumors. However, despite its potential, the use of TMB as a biomarker for immunotherapy efficacy is limited by several factors. Here we review the limitations of TMB in predicting immunotherapy outcomes in patients with cancer and discuss potential strategies to optimize its use in the clinic.

KEAP1-Mutant Lung Cancers Weaken Anti-Tumor Immunity and Promote an M2-like Macrophage Phenotype

Considerable advances have been made in lung cancer therapies, but there is still an unmet clinical need to improve survival for lung cancer patients. Immunotherapies have improved survival, although only 20-30% of patients respond to these treatments. Interestingly, cancers with mutations in Kelch-like ECH-associated protein 1 (KEAP1), the negative regulator of the nuclear factor erythroid 2-related factor 2 (NRF2) transcription factor, are resistant to immune checkpoint inhibition and correlate with decreased lymphoid cell infiltration. NRF2 is known for promoting an anti-inflammatory phenotype when activated in immune cells, but the study of NRF2 activation in cancer cells has not been adequately assessed. The objective of this study was to determine how lung cancer cells with constitutive NRF2 activity interact with the immune microenvironment to promote cancer progression. To assess, we generated CRISPR-edited mouse lung cancer cell lines by knocking out the KEAP1 or NFE2L2 genes and utilized a publicly available single-cell dataset through the Gene Expression Omnibus to investigate tumor/immune cell interactions. We show here that KEAP1-mutant cancers promote immunosuppression of the tumor microenvironment. Our data suggest KEAP1 deletion is sufficient to alter the secretion of cytokines, increase expression of immune checkpoint markers on cancer cells, and alter recruitment and differential polarization of immunosuppressive macrophages that ultimately lead to T-cell suppression.

Exploiting the therapeutic implications of KRAS inhibition on tumor immunity

Over the past decade, RAS oncogenic proteins have transitioned from being deemed undruggable to having two clinically approved drugs, with several more in advanced stages of development. Despite the initial benefit of KRAS-G12C inhibitors for patients with tumors harboring this mutation, the rapid emergence of drug resistance underscores the urgent need to synergize these inhibitors with other therapeutic approaches to improve outcomes. RAS mutant tumor cells can create an immunosuppressive tumor microenvironment (TME), suggesting an increased susceptibility to immunotherapies following RAS inhibition. This provides a rationale for combining RAS inhibitory drugs with immune checkpoint blockade (ICB). However, achieving this synergy in the clinical setting has proven challenging. Here, we explore how understanding the impact of RAS mutant tumor cells on the TME can guide innovative approaches to combining RAS inhibition with immunotherapies, review progress in both pre-clinical and clinical stages, and discuss challenges and future directions.

Pulmonary Adenocarcinoma In Situ and Minimally Invasive Adenocarcinomas in European Patients Have Less KRAS and More EGFR Mutations Compared to Advanced Adenocarcinomas

Pulmonary adenocarcinoma (ADC) is a very diverse disease, both genetically and histologically, which displays extensive intratumor heterogeneity with numerous acquired mutations. ADC is the most common type of lung cancer and is believed to arise from adenocarcinoma in situ (AIS) which then progresses to minimally invasive adenocarcinoma (MIA). In patients of European ethnicity, we analyzed genetic mutations in AIS (n = 10) and MIA (n = 18) and compared the number of genetic mutations with advanced ADC (n = 2419). Using next-generation sequencing, the number of different mutations detected in both AIS (87.5%) and MIA (94.5%) were higher (p < 0.001) than in advanced ADC (53.7%). In contrast to the high number of mutations in Kirsten rat sarcoma virus gene (KRAS) in advanced ADC (34.6%), there was only one case of AIS with KRAS G12C mutation (3.5%; p < 0.001) and no cases of MIA with KRAS mutation (p < 0.001). In contrast to the modest prevalence of epidermal growth factor receptor (EGFR) mutations in advanced ADC (15.0%), the fraction of EGFR mutant cases was higher in both in AIS (22.2%) and MIA (59.5%; p < 0.001). The EGFR exon 19 deletion mutation was more common in both MIA (50%; n = 6/12) and ADC (41%; n = 149/363), whereas p.L858R was more prevalent in AIS (75%; n = 3/4). In contrast to pulmonary advanced ADC, KRAS driver mutations are less common, whereas mutations in EGFR are more common, in detectable AIS and MIA.

Clinical and Genomic Characterization of Long-Term Responders Receiving Immune Checkpoint Blockade for Metastatic Non-Small-Cell Lung Cancer

OBJECTIVES

Understand from a real-world cohort the unique clinical and genomic determinants of a durable response to immune checkpoint inhibitors (ICIs).

MATERIALS AND METHODS

This is a retrospective study of patients with NSCLC who received any ICI-based regimen as first or second line therapy. Long-term responders (LTR) achieved an overall survival (OS) ≥ 3 years from time of treatment start, while nonresponders (NR) were patients who had an OS of 6 to 12 months from time of treatment start. Clinical and demographic covariables were collected from electronic medical records. Fisher's exact test and Mann-Whitney test were used to analyze the association of a long-term response to ICI in relation to clinical and genomic variables. All P-values were considered significant at P-value < .05.

RESULTS

A total of 72 patients were included in this study (LTR n = 37, NR n = 35). There were no significant differences in age, sex, race, and BMI between groups. The presence of liver metastases at the time of ICI initiation and PD-L1 status were not associated with LTR to ICIs. Patients in the LTR were more likely to experience irAEs at 3-,6- and 12-months. KRAS mutant tumors were numerically more common in the LTR group (n = 13 vs. 8).

CONCLUSION

We observe no strong clinical and biomarkers of a prolonged response to ICIs. Additional large prospective cohort studies are needed to investigate the genomic footprint of long-term responders.

Clinical Benefit from Docetaxel +/- Ramucirumab Is Not Associated with Mutation Status in Metastatic Non-Small-Cell Lung Cancer Patients Who Progressed on Platinum Doublets and Immunotherapy

Docetaxel +/- ramucirumab remains the standard-of-care therapy for patients with metastatic non-small-cell lung cancer (NSCLC) after progression on platinum doublets and immune checkpoint inhibitors (ICIs). The aim of our study was to investigate whether the cancer gene mutation status was associated with clinical benefits from docetaxel +/- ramucirumab. We also investigated whether platinum/taxane-based regimens offered a better clinical benefit in this patient population. A total of 454 patients were analyzed (docetaxel +/- ramucirumab n=381; platinum/taxane-based regimens n=73). Progression-free survival (PFS) and overall survival (OS) were compared among different subpopulations with different cancer gene mutations and between patients who received docetaxel +/- ramucirumab versus platinum/taxane-based regimens. Among patients who received docetaxel +/- ramucirumab, the top mutated cancer genes included TP53 (n=167), KRAS (n=127), EGFR (n=65), STK11 (n=32), ERBB2 (HER2) (n=26), etc. None of these cancer gene mutations or PD-L1 expression was associated with PFS or OS. Platinum/taxane-based regimens were associated with a significantly longer mQS (13.00 m, 95% Cl: 11.20-14.80 m versus 8.40 m, 95% Cl: 7.12-9.68 m, LogRank P=0.019) than docetaxel +/- ramcirumab. Key prognostic factors including age, histology, and performance status were not different between these two groups. In conclusion, in patients with metastatic NSCLC who have progressed on platinum doublets and ICIs, the clinical benefit from docetaxel +/- ramucirumab is not associated with the cancer gene mutation status. Platinum/taxane-based regimens may offer a superior clinical benefit over docetaxel +/- ramucirumab in this patient population.

Unveiling the role of KRAS in tumor immune microenvironment

Kirsten rats sarcoma viral oncogene (KRAS), the first discovered human oncogene, has long been recognized as "undruggable". KRAS mutations frequently occur in multiple human cancers including non-small cell lung cancer(NSCLC), colorectal cancer(CRC) and pancreatic ductal adenocarcinoma(PDAC), functioning as a "molecule switch" determining the activation of various oncogenic signaling pathways. Except for its intrinsic pro-tumorigenic role, KRAS alteration also exhibits an unique immune signature characterized by elevated PD-L1 level and high tumor mutational burden(TMB). KRAS mutation shape an immune suppressive microenvironment by impeding effective T cells infiltration and recruiting suppressive immune cells including myeloid-derived suppressor cells(MDSCs), regulatory T cells(Tregs), cancer associated fibroblasts(CAFs). In immune checkpoint inhibitor(ICI) era, NSCLC patients with mutated KRAS tend to be more responsive to ICI than patients with intact KRAS. The hallmark for KRAS mutation is the existence of multiple kinds of co-mutations. Different types of co-alterations have distinct tumor microenvironment(TME) signatures and responses to ICI. TP53 co-mutation possess a "hot" TME and achieve higher response to immunotherapy while other loss of function mutation correlated with a "colder" TME and a poor outcome to ICI-based therapy. The groundbreaking discovery of KRAS G12C inhibitors significantly improved outcomes for this KRAS subtype even though efficacy was limited to NSCLC patients. KRAS G12C inhibitors also restore the suppressive TME, creating an opportunity for combinations with ICI. However, an inevitable challenge to KRAS inhibitors is drug resistance. Promising combination strategies such as combination with SHP2 is an approach deserve further exploration because of their immune modulatory effect.

Outcomes following KRASG12C inhibitor treatment in patients with KRASG12C-mutated solid tumors: A systematic review and meta-analysis

OBJECTIVE

To assess the efficacy and safety of FDA-approved KRASG12C inhibitors in patients with KRASG12C-mutated solid tumors.

METHODS

We searched PubMed, EMBASE, Cochrane Library, and major international conferences for clinical trials published in English up to March 6, 2023. Clinical trials investigating sotorasib or adagrasib and reporting the clinical outcomes of the objective response rate (ORR), disease control rate (DCR), or incidence rate of grade ≥ 3 adverse events (AEs) were eligible. The primary endpoint was the ORR. Secondary endpoints included the DCR, incidence rate of grade ≥ 3 AEs, and odds ratio (OR) of the ORR between patients with or without co-mutation. The Random-effects model was applied for the outcomes of interest.

RESULTS

18 studies with 1224 patients were included in this meta-analysis. The pooled ORR, DCR, and incidence rate of grade ≥ 3 AEs were 31 % (95 % CI, 25-37 %), 86 % (95 % CI, 82-89 %), and 29 % (95 % CI, 23-36 %), respectively. KRASG12C-mutated NSCLC patients with a co-mutation of KEAP1 exhibited a worse ORR than those with wild-type KEAP1 (OR: 0.35, 95 % CI: 0.16-0.77).

CONCLUSIONS

This study provided a comprehensive understanding of the efficacy and safety of KRASG12C inhibitors in treating solid tumors and identified KEAP1 mutation as a potential predictive biomarker of inferior response in patients treated with KRASG12C inhibitors. These findings may assist in the design of future clinical trials for identifying populations that may benefit from KRASG12C inhibitor treatment.

Oncogenic KEAP1 mutations activate TRAF2-NFκB signaling to prevent apoptosis in lung cancer cells

The Kelch-like ECH-associated protein 1 (KEAP1) - Nuclear factor erythroid 2 -related factor 2 (NRF2) pathway is the major transcriptional stress response system in cells against oxidative and electrophilic stress. NRF2 is frequently constitutively active in many cancers, rendering the cells resistant to chemo- and radiotherapy. Loss-of-function (LOF) mutations in the repressor protein KEAP1 are common in non-small cell lung cancer, particularly adenocarcinoma. While the mutations can occur throughout the gene, they are enriched in certain areas, indicating that these may have unique functional importance. In this study, we show that in the GSEA analysis of TCGA lung adenocarcinoma RNA-seq data, the KEAP1 mutations in R320 and R470 were associated with enhanced Tumor Necrosis Factor alpha (TNFα) - Nuclear Factor kappa subunit B (NFκB) signaling as well as MYC and MTORC1 pathways. To address the functional role of these hotspot mutations, affinity purification and mass spectrometry (AP-MS) analysis of wild type (wt) KEAP1 and its mutation forms, R320Q and R470C were employed to interrogate differences in the protein interactome. We identified TNF receptor associated factor 2 (TRAF2) as a putative protein interaction partner. Both mutant KEAP1 forms showed increased interaction with TRAF2 and other anti-apoptotic proteins, suggesting that apoptosis signalling could be affected by the protein interactions. A549 lung adenocarcinoma cells overexpressing mutant KEAP1 showed high TRAF2-mediated NFκB activity and increased protection against apoptosis, XIAP being one of the key proteins involved in anti-apoptotic signalling. To conclude, KEAP1 R320Q and R470C and its interaction with TRAF2 leads to activation of NFκB pathway, thereby protecting against apoptosis.

Abnormalities in the KRAS Gene and Treatment Options for NSCLC Patients with the G12C Mutation in This Gene-A Literature Review and Single-Center Experience

Mutations in the KRAS gene are among the most common mutations observed in cancer cells, but they have only recently become an achievable goal for targeted therapies. Two KRAS inhibitors, sotorasib and adagrasib, have recently been approved for the treatment of patients with advanced non-small cell lung cancer with the KRAS G12C mutation, while studies on their efficacy are still ongoing. In this work, we comprehensively analyzed RAS gene mutations' molecular background, mutation testing, KRAS inhibitors' effectiveness with an emphasis on non-small cell lung cancer, the impact of KRAS mutations on immunotherapy outcomes, and drug resistance problems. We also summarized ongoing trials and analyzed emerging perspectives on targeting KRAS in cancer patients.

KRASG12C mutant lung adenocarcinoma: unique biology, novel therapies and new challenges

KRAS mutant lung cancer is the most prevalent molecular subclass of adenocarcinoma (LUAD), which is a heterogenous group depending on the mutation-type which affects not only the function of the oncogene but affects the biological behavior of the cancer as well. Furthermore, KRAS mutation affects radiation sensitivity but leads also to bevacizumab and bisphosphonate resistance as well. It was highly significant that allele specific irreversible inhibitors have been developed for the smoking associated G12C mutant KRAS (sotorasib and adagrasib). Based on trial data both sotorasib and adagrasib obtained conditional approval by FDA for the treatment of previously treated advanced LUAD. Similar to other target therapies, clinical administration of KRASG12C inhibitors (sotorasib and adagrasib) resulted in acquired resistance due to various genetic changes not only in KRAS but in other oncogenes as well. Recent clinical studies are aiming to increase the efficacy of G12C inhibitors by novel combination strategies.

Unveiling the potential of proteomic and genetic signatures for precision therapeutics in lung cancer management

Lung cancer's enduring global significance necessitates ongoing advancements in diagnostics and therapeutics. Recent spotlight on proteomic and genetic biomarker research offers a promising avenue for understanding lung cancer biology and guiding treatments. This review elucidates genetic and proteomic lung cancer biomarker progress and their treatment implications. Technological strides in mass spectrometry-based proteomics and next-generation sequencing enable pinpointing of genetic abnormalities and abnormal protein expressions, furnishing vital data for precise diagnosis, patient classification, and customized treatments. Biomarker-driven personalized medicine yields substantial treatment improvements, elevating survival rates and minimizing adverse effects. Integrating omics data (genomics, proteomics, etc.) enhances understanding of lung cancer's intricate biological milieu, identifying novel treatment targets and biomarkers, fostering precision medicine. Liquid biopsies, non-invasive tools for real-time treatment monitoring and early resistance detection, gain popularity, promising enhanced management and personalized therapy. Despite advancements, biomarker repeatability and validation challenges persist, necessitating interdisciplinary efforts and large-scale clinical trials. Integrating artificial intelligence and machine learning aids analyzing vast omics datasets and predicting treatment responses. Single-cell omics reveal cellular connections and intratumoral heterogeneity, valuable for combination treatments. Biomarkers enable accurate diagnosis, tailored medicines, and treatment response tracking, significantly impacting personalized lung cancer care. This approach spurs patient-centered trials, empowering active patient engagement. Lung cancer proteomic and genetic biomarkers illuminate disease biology and treatment prospects. Progressing towards individualized efficient therapies is imminent, alleviating lung cancer's burden through ongoing research, omics integration, and technological strides.

Genome-Wide CRISPR Screens Identify Multiple Synthetic Lethal Targets That Enhance KRASG12C Inhibitor Efficacy

Non-small lung cancers (NSCLC) frequently (∼30%) harbor KRAS driver mutations, half of which are KRASG12C. KRAS-mutant NSCLC with comutated STK11 and/or KEAP1 is particularly refractory to conventional, targeted, and immune therapy. Development of KRASG12C inhibitors (G12Ci) provided a major therapeutic advance, but resistance still limits their efficacy. To identify genes whose deletion augments efficacy of the G12Cis adagrasib (MRTX-849) or adagrasib plus TNO155 (SHP2i), we performed genome-wide CRISPR/Cas9 screens on KRAS/STK11-mutant NSCLC lines. Recurrent, potentially targetable, synthetic lethal (SL) genes were identified, including serine-threonine kinases, tRNA-modifying and proteoglycan synthesis enzymes, and YAP/TAZ/TEAD pathway components. Several SL genes were confirmed by siRNA/shRNA experiments, and the YAP/TAZ/TEAD pathway was extensively validated in vitro and in mice. Mechanistic studies showed that G12Ci treatment induced gene expression of RHO paralogs and activators, increased RHOA activation, and evoked ROCK-dependent nuclear translocation of YAP. Mice and patients with acquired G12Ci- or G12Ci/SHP2i-resistant tumors showed strong overlap with SL pathways, arguing for the relevance of the screen results. These findings provide a landscape of potential targets for future combination strategies, some of which can be tested rapidly in the clinic.

SIGNIFICANCE

Identification of synthetic lethal genes with KRASG12C using genome-wide CRISPR/Cas9 screening and credentialing of the ability of TEAD inhibition to enhance KRASG12C efficacy provides a roadmap for combination strategies. See related commentary by Johnson and Haigis, p. 4005.

Facts and Hopes on RAS Inhibitors and Cancer Immunotherapy

Although the past decade has seen great strides in the development of immunotherapies that reactivate the immune system against tumors, there have also been major advances in the discovery of drugs blocking oncogenic drivers of cancer growth. However, there has been very little progress in combining immunotherapies with drugs that target oncogenic driver pathways. Some of the most important oncogenes in human cancer encode RAS family proteins, although these have proven challenging to target. Recently drugs have been approved that inhibit a specific mutant form of KRAS: G12C. These have improved the treatment of patients with lung cancer harboring this mutation, but development of acquired drug resistance after initial responses has limited the impact on overall survival. Because of the immunosuppressive nature of the signaling network controlled by oncogenic KRAS, targeted KRAS G12C inhibition can indirectly affect antitumor immunity, and does so without compromising the critical role of normal RAS proteins in immune cells. This serves as a rationale for combination with immune checkpoint blockade, which can provide additional combinatorial therapeutic benefit in some preclinical cancer models. However, in clinical trials, combination of KRAS G12C inhibitors with PD-(L)1 blockade has yet to show improved outcome, in part due to treatment toxicities. A greater understanding of how oncogenic KRAS drives immune evasion and how mutant-specific KRAS inhibition impacts the tumor microenvironment can lead to novel approaches to combining RAS inhibition with immunotherapies.

SOS1 inhibition enhances the efficacy of and delays resistance to G12C inhibitors in lung adenocarcinoma

Clinical effectiveness of KRAS G12C inhibitors (G12Cis) is limited both by intrinsic and acquired resistance, necessitating the development of combination approaches. We found that targeting proximal receptor tyrosine kinase (RTK) signaling using the SOS1 inhibitor (SOS1i) BI-3406 both enhanced the potency of and delayed resistance to G12Ci treatment, but the extent of SOS1i effectiveness was modulated by both SOS2 expression and the specific mutational landscape. SOS1i enhanced the efficacy of G12Ci and limited rebound RTK/ERK signaling to overcome intrinsic/adaptive resistance, but this effect was modulated by SOS2 protein levels. Survival of drug-tolerant persister (DTP) cells within the heterogeneous tumor population and/or acquired mutations that reactivate RTK/RAS signaling can lead to outgrowth of tumor initiating cells (TICs) that drive therapeutic resistance. G12Ci drug tolerant persister cells showed a 2-3-fold enrichment of TICs, suggesting that these could be a sanctuary population of G12Ci resistant cells. SOS1i re-sensitized DTPs to G12Ci and inhibited G12C-induced TIC enrichment. Co-mutation of the tumor suppressor KEAP1 limits the clinical effectiveness of G12Cis, and KEAP1 and STK11 deletion increased TIC frequency and accelerated the development of acquired resistance to G12Ci in situ. SOS1i both delayed acquired G12Ci resistance and limited the total number of resistant colonies regardless of KEAP1 and STK11 mutational status. These data suggest that SOS1i could be an effective strategy to both enhance G12Ci efficacy and prevent G12Ci resistance regardless of co-mutations.

Prognostic value of KRAS mutations, TP53 mutations and PD-L1 expression among lung adenocarcinomas treated with immunotherapy

AIMS

The aim of this study was to investigate the association between oncogenic alterations and programmed cell death ligand 1 (PD-L1) expression in lung adenocarcinomas, as well as the prognostic value of KRAS and/or TP53 mutations in patients treated with immunotherapy.

METHODS

This study is a retrospective cohort study of 519 patients with lung adenocarcinomas analysed for mutations and PD-L1 expression. Data were collected from electronic pathology record system, next-generation sequencing system, and clinical databases. Association between mutations and PD-L1 expression was investigated, as well as survival statistics of the 65 patients treated with immunotherapy.

RESULTS

41% of the samples contained a KRAS mutation, predominantly together with mutations in TP53 (41%) or STK11 (10%). Higher expression of PD-L1 was seen among patients with KRAS mutations (p=0.002) and EGFR wild type (p=0.006). For patients treated with immunotherapy, there was no statistically significant difference for overall survival (OS) and progression-free survival (PFS) according to KRAS mutation status, TP53 mutation status or PD-L1 expression. The HR for concomitant mutations in TP53 and KRAS was 0.78 (95% CI 0.62 to 0.99) for OS and 0.43 (0.21 to 0.88) for PFS. Furthermore, concomitant TP53 and KRAS mutations predicted a better PFS (p=0.015) and OS (p=0.029) compared with no mutations or a single mutation in either TP53 or KRAS.

CONCLUSION

Mutations in TP53 together with KRAS may serve as a potential biomarker for survival benefits with immunotherapy.

ATM Mutations Associate with Distinct Co-Mutational Patterns and Therapeutic Vulnerabilities in NSCLC

PURPOSE

Ataxia-telangiectasia mutated (ATM) is the most frequently mutated DNA damage repair gene in non-small cell lung cancer (NSCLC). However, the molecular correlates of ATM mutations and their clinical implications have not been fully elucidated.

EXPERIMENTAL DESIGN

Clinicopathologic and genomic data from 26,587 patients with NSCLC from MD Anderson, public databases, and a de-identified nationwide (US-based) NSCLC clinicogenomic database (CGDB) were used to assess the co-mutation landscape, protein expression, and mutational processes in ATM-mutant tumors. We used the CGDB to evaluate ATM-associated outcomes in patients treated with immune checkpoint inhibitors (ICI) with or without chemotherapy, and assessed the effect of ATM loss on STING signaling and chemotherapy sensitivity in preclinical models.

RESULTS

Nonsynonymous mutations in ATM were observed in 11.2% of samples (2,980/26,587) and were significantly associated with mutations in KRAS, but mutually exclusive with EGFR (q < 0.1). KRAS mutational status constrained the ATM co-mutation landscape, with strong mutual exclusivity with TP53 and KEAP1 within KRAS-mutated samples. Those ATM mutations that co-occurred with TP53 were more likely to be missense mutations and associate with high mutational burden, suggestive of non-functional passenger mutations. In the CGDB cohort, dysfunctional ATM mutations associated with improved OS only in patients treated with ICI-chemotherapy, and not ICI alone. In vitro analyses demonstrated enhanced upregulation of STING signaling in ATM knockout cells with the addition of chemotherapy.

CONCLUSIONS

ATM mutations define a distinct subset of NSCLC associated with KRAS mutations, increased TMB, decreased TP53 and EGFR co-occurrence, and potential increased sensitivity to ICIs in the context of DNA-damaging chemotherapy.

Characterization of 164 patients with NRAS mutated non-small cell lung cancer (NSCLC)

BACKGROUND

NRAS mutations are observed in less than 1% of non-small cell lung cancer (NSCLC). Clinical data regarding this rare subset of lung cancer are scarce and response to systemic treatment such as chemotherapy or immune checkpoint inhibitors (ICI) has never been reported.

METHODS

All consecutive patients with an NRAS mutated NSCLC, diagnosed between August 2014 and November 2020 in 14 French centers, were included. Clinical and molecular data were collected and reviewed from medical records.

RESULTS

Out of the 164 included patients, 106 (64.6%) were men, 150 (91.5%) were current or former smokers, and 104 (63.4%) had stage IV NSCLC at diagnosis. The median age was 62 years, and the most frequent histology was adenocarcinoma (81.7%). NRAS activating mutations were mostly found in codon 61 (70%), while codon 12 and 13 alterations were observed in 16.5% and 4.9% of patients, respectively. Programmed death ligand-1 expression level <1%/1-49%/≥50% were respectively found in 30.8%/27.1%/42.1% of tumors. With a median follow-up of 12.5 months, median overall survival (OS) of stage IV patients was 15.3 months (95% CI 9.9-27.6). No significant difference in OS was found according to the type of mutation (codon 61 vs. other), HR = 1.12 (95% CI 0.65-1.95). Among stage IV patients treated with platinum-based doublet (n = 66), ICI (n = 48), or combination of both (n = 10), objective response rate, and median progression free survival were respectively 45% and 5.8 months, 35% and 6.9 months, 70% and 8.6 months.

CONCLUSION

NRAS mutated NSCLC are characterized by a high frequency of smoking history and codon 61 mutations. Further studies are needed to confirm the encouraging outcome of immunotherapy in combination with chemotherapy.

Baseline mutational profiles of patients with carcinoma of unknown primary origin enrolled in the CUPISCO study

BACKGROUND

Patients with unfavorable carcinoma of unknown primary origin (CUP) have an extremely poor prognosis of ∼1 year or less, stressing the need for more tailored treatments, which are currently being tested in clinical trials. CUPISCO (NCT03498521) was a phase II randomized study of targeted therapy/cancer immunotherapy versus platinum-based chemotherapy in patients with previously untreated, unfavorable CUP, defined as per the European Society for Medical Oncology guidelines. We present a preliminary, descriptive molecular analysis of 464 patients with stringently diagnosed, unfavorable CUP enrolled in the CUPISCO study.

MATERIALS AND METHODS

Genomic profiling was carried out on formalin-fixed, paraffin-embedded tissue to detect genomic alterations and assess tumor mutational burden and microsatellite instability.

RESULTS

Overall, ∼32% of patients carried a potentially targetable genomic alteration, including PIK3CA, FGFR2, ERBB2, BRAFV600E, EGFR, MET, NTRK1, ROS1, and ALK. Using hierarchical clustering of co-mutational profiles, 10 clusters were identified with specific genomic alteration co-occurrences, with some mirroring defined tumor entities.

CONCLUSIONS

Results reveal the molecular heterogeneity of patients with unfavorable CUP and suggest that genomic profiling may be used as part of informed decision-making to identify the potential primary tumor and targeted treatment options. Whether stringently diagnosed patients with unfavorable CUP benefit from targeted therapies in a similar manner to those with matched known primaries will be a key learning from CUPISCO.

KEAP1 mutation in lung adenocarcinoma promotes immune evasion and immunotherapy resistance

Lung cancer treatment has benefited greatly through advancements in immunotherapies. However, immunotherapy often fails in patients with specific mutations like KEAP1, which are frequently found in lung adenocarcinoma. We established an antigenic lung cancer model and used it to explore how Keap1 mutations remodel the tumor immune microenvironment. Using single-cell technology and depletion studies, we demonstrate that Keap1-mutant tumors diminish dendritic cell and T cell responses driving immunotherapy resistance. This observation was corroborated in patient samples. CRISPR-Cas9-mediated gene targeting revealed that hyperactivation of the NRF2 antioxidant pathway is responsible for diminished immune responses in Keap1-mutant tumors. Importantly, we demonstrate that combining glutaminase inhibition with immune checkpoint blockade can reverse immunosuppression, making Keap1-mutant tumors susceptible to immunotherapy. Our study provides new insight into the role of KEAP1 mutations in immune evasion, paving the way for novel immune-based therapeutic strategies for KEAP1-mutant cancers.

Immunoediting of KEAP1-NRF2 mutant tumours is required to circumvent NRF2-mediated immune surveillance

In human cancer, activating mutations in the KEAP1-NRF2 pathway are frequently observed, and positively selected for, as they confer the cytoprotective functions of the transcription factor NRF2 on the cancer cells. This results in the development of aggressive tumours which are resistant to treatment with chemotherapeutic compounds. Recent clinical developments have also revealed that NRF2-activated cancers are similarly resistant to immune checkpoint inhibitor drugs. As the mechanism of action of these immune modulating therapies is tangential to the classical cytoprotective function of NRF2, it is unclear how aberrant NRF2 activity could impact the anti-cancer functionality of the immune system. In this context, we found that in human cancer, NRF2-activated cells are highly immunoedited, which allows the cancer cells to escape immune surveillance and develop into malignant tumours. This immunoediting takes the form of reduced antigen presentation by the MHC-I complex, coupled with reduced expression of activating ligands for NK cells. Together, these modifications to the immunogenicity of NRF2-activated cancers inhibit immune effector cell infiltration and engagement, and contribute to the formation of the immunologically cold tumour microenvironment which is a characteristic feature of NRF2-activated cancers.

Next batter up! Targeting cancers with KRAS-G12D mutations

KRAS is the most frequently mutated oncogene in cancer. Activating mutations in codon 12, especially G12D, have the highest prevalence across a range of carcinomas and adenocarcinomas. With inhibitors to KRAS-G12D now entering clinical trials, understanding the biology of KRAS-G12D cancers, and identifying biomarkers that predict therapeutic response is crucial. In this Review, we discuss the genomics and biology of KRAS-G12D adenocarcinomas, including histological features, transcriptional landscape, the immune microenvironment, and how these factors influence response to therapy. Moreover, we explore potential therapeutic strategies using novel G12D inhibitors, leveraging knowledge gained from clinical trials using G12C inhibitors.

Optimal Therapeutic Strategy for PD-L1 Negative Metastatic Non-Small Cell Lung Cancer: A Decision-Making Guide Based on Clinicopathological and Molecular Features

OPINION STATEMENT

Strategies using immune checkpoint inhibitors (ICI), which can enhance antitumor immune responses, have revolutionized the lung cancer therapeutic landscape. The ICI mechanism of action involves the blockade of regulatory cell surface molecules using antibodies against the Cytotoxic T-Lymphocyte Antigen 4 (CTLA-4) (ipilimumab, tremelimumab); the programmed death receptor-1 (PD-1; nivolumab, pembrolizumab); or the PD ligand-1 (PD-L1; atezolizumab, durvalumab). Notably, anti-PD-1 demonstrated long-term survival benefits, durable objective responses, and a manageable safety profile in patients with non-small cell lung cancer (NSCLC). The combination of anti-PD1 or anti-PD-L1 and platinum chemotherapy achieved better survival outcomes than chemotherapy alone, which was observed irrespective of PD-L1 expression on cancer cells. Although promising results have been reported from large clinical trials, especially for patients with high PD-L1 expression, the optimal treatment approach for patients with PD-L1-negative NSCLC has yet to be defined. We propose a guide for clinicians in the therapeutic decision-making process based on the latest data available about treatments, prognostic factors, predictive biomarkers, and real-world evidence in PD-L1-negative NSCLC patients.

Integration of signaling pathway and bromodomain and extra-terminal domain inhibition for the treatment of mutant Kirsten rat sarcoma viral oncogene homolog cancer

Mutant Kirsten rat sarcoma viral oncogene homolog (KRAS) is now a drugable oncogenic driver and the KRAS G12C variant responds clinically to sotorasib and adagrasib that covalently block the cysteine of the active center and inhibit downstream signaling and proliferation. Unfortunately, progression-free survival (PFS) of lung cancer patients is only 5-6 months and no survival advantage has been found for sotorasib in comparison to docetaxel chemotherapy. Increased responses to KRAS inhibitors are tested in combination with the son of sevenless 1 (SOS1) inhibitors, upstream and downstream signaling modulators as well as chemotherapeutics. Some of these approaches are limited by toxicity to normal tissues and by diverse mechanisms of resistance. In essence, most of these attempts are directed to the inhibition of proliferation by impairment of the signal transduction pathways. The final target of KRAS-mediated growth stimulation is MYC in the cell nucleus that stimulates transcription of a host of genes. In detail, MYC alters genomic enhancer and super-enhancers of transcription that are frequently deregulated in cancer. Such enhancers can be targeted by bromodomain and extra-terminal (BET) inhibitors (BETi) or degraders and this review discusses whether integrated SOS1 inhibition and BET targeting of MYC synergizes against mutant KRAS tumor growth. BET degraders in the form of proteolysis-targeting chimeras (PROTACs) combined with BAY-293-mediated SOS1 inhibition revealed marked cytotoxic synergy against mutant KRAS cancer cells and may constitute a promising option for clinical treatment.

Concurrent Mutations in STK11 and KEAP1 Cause Treatment Resistance in KRAS Wild-type Non-small-cell Lung Cancer

We herein report a patient with KRAS wild-type non-small-cell lung cancer (NSCLC) with concurrent STK11 and KEAP1 mutations. A 53-year-old man visited a local doctor with a complaint of left shoulder swelling and pain. He was diagnosed with NSCLC cT4N0M1c stage IVB. A comprehensive genome profile test revealed mutations in STK11 and KEAP1 but no KRAS mutations. The patient was refractory to radiotherapy, immunotherapy, and chemotherapy. Thus, STK11 and KEAP1 mutations can be considered resistance mutations that confer resistance to various anticancer therapies in KRAS wild-type NSCLC.

Acquired resistance to KRAS G12C small-molecule inhibitors via genetic/nongenetic mechanisms in lung cancer

Inherent or acquired resistance to sotorasib poses a substantialt challenge for NSCLC treatment. Here, we demonstrate that acquired resistance to sotorasib in isogenic cells correlated with increased expression of integrin β4 (ITGB4), a component of the focal adhesion complex. Silencing ITGB4 in tolerant cells improved sotorasib sensitivity, while overexpressing ITGB4 enhanced tolerance to sotorasib by supporting AKT-mTOR bypass signaling. Chronic treatment with sotorasib induced WNT expression and activated the WNT/β-catenin signaling pathway. Thus, silencing both ITGB4 and β-catenin significantly improved sotorasib sensitivity in tolerant, acquired, and inherently resistant cells. In addition, the proteasome inhibitor carfilzomib (CFZ) exhibited synergism with sotorasib by down-regulating ITGB4 and β-catenin expression. Furthermore, adagrasib phenocopies the combination effect of sotorasib and CFZ by suppressing KRAS activity and inhibiting cell cycle progression in inherently resistant cells. Overall, our findings unveil previously unrecognized nongenetic mechanisms underlying resistance to sotorasib and propose a promising treatment strategy to overcome resistance.

Cancer cell-intrinsic mechanisms driving acquired immune tolerance

Immune evasion is a hallmark of cancer, enabling tumors to survive contact with the host immune system and evade the cycle of immune recognition and destruction. Here, we review the current understanding of the cancer cell-intrinsic factors driving immune evasion. We focus on T cells as key effectors of anti-cancer immunity and argue that cancer cells evade immune destruction by gaining control over pathways that usually serve to maintain physiological tolerance to self. Using this framework, we place recent mechanistic advances in the understanding of cancer immune evasion into broad categories of control over T cell localization, antigen recognition, and acquisition of optimal effector function. We discuss the redundancy in the pathways involved and identify knowledge gaps that must be overcome to better target immune evasion, including the need for better, routinely available tools that incorporate the growing understanding of evasion mechanisms to stratify patients for therapy and trials.

G6PD Maintains Redox Homeostasis and Biosynthesis in LKB1-Deficient KRAS-Driven Lung Cancer

Cancer cells depend on nicotinamide adenine dinucleotide phosphate (NADPH) to combat oxidative stress and support reductive biosynthesis. One major NAPDH production route is the oxidative pentose phosphate pathway (committed step: glucose-6-phosphate dehydrogenase, G6PD). Alternatives exist and can compensate in some tumors. Here, using genetically-engineered lung cancer model, we show that ablation of G6PD significantly suppresses KrasG12D/+;Lkb1-/- (KL) but not KrasG12D/+;p53-/- (KP) lung tumorigenesis. In vivo isotope tracing and metabolomics revealed that G6PD ablation significantly impaired NADPH generation, redox balance and de novo lipogenesis in KL but not KP lung tumors. Mechanistically, in KL tumors, G6PD ablation caused p53 activation that suppressed tumor growth. As tumor progressed, G6PD-deficient KL tumors increased an alternative NADPH source, serine-driven one carbon metabolism, rendering associated tumor-derived cell lines sensitive to serine/glycine depletion. Thus, oncogenic driver mutations determine lung cancer dependence on G6PD, whose targeting is a potential therapeutic strategy for tumors harboring KRAS and LKB1 co-mutations.

Comparative bioinformatic analysis of KRAS, STK11 and KEAP1 (co-)mutations in non-small cell lung cancer with a special focus on KRAS G12C

OBJECTIVES

Mutations in STK11 (STK11MUT) and KEAP1 (KEAP1MUT) occur frequently in non-small cell lung cancer (NSCLC) and are often co-mutated with KRAS. Several studies linked the co-occurrence of KRASMUT + STK11MUT, as well as KRASMUT + KEAP1MUT to reduced response to immune checkpoint inhibitors (ICI) and even a negative impact on survival. Data focusing STK11 + KEAP1 co-mutations or the triple mutation (KRAS + STK11 + KEAP1) are scarce. The recent availability of KRAS-G12C inhibitors increases the clinical relevance of those co-mutations in KRAS-mutated NSCLC.

MATERIALS AND METHODS

We present a comprehensive bioinformatic analysis encompassing six datasets retrieved from cBioPortal.

RESULTS

Independent of the treatment, triple mutations and STK11MUT + KEAP1MUT were significantly associated with a reduced overall survival (OS). Across treatments, OS of patients with a KRAS G12C triple mutation was significantly reduced compared to patients with KRAS G12C-only. Under ICI-therapy, there was no significant difference in OS between patients harboring the KRAS G12C-only and patients with the KRAS G12C triple mutation, but a significant difference between patients harboring KRAS non-G12C and KRAS non-G12C triple mutations. Triple mutated primary tumors showed a significantly increased frequency of distant metastases to bone and adrenal glands compared to KRAS-only mutated tumors. Additionally, our drug response analysis in cancer cell lines harboring the triple mutations revealed the WNT pathway inhibitor XAV-939 as a potential future drug candidate for this mutational situation.

CONCLUSION

The triple mutation status may serve as a negative prognostic and predictive factor across treatments compared to KRASMUT-only. KRAS G12C generally seems to be a negative predictive marker for ICI-therapy.